This invention relates to a sliding guide for a floating caliper of a disc brake, in particular for automotive vehicles, wherein a brake support member has four surfaces spaced from each other to guide the caliper in an axial direction, and wherein the caliper bears against a first pair of the four guiding surfaces radially from the inside and against a second pair of the four guiding surfaces radially from the outside.
In a known sliding guide of this type, as shown, for example, in German Patent DE-OS No. 2,408,519, grooves are provided in the lateral ends of the caliper which are engaged axially by spaced, prismatic guiding pins fastened to arms of the brake support member. A clip spring bearing against the brake support member acts on the caliper in a radial direction such that on the one side of the brake disc the radially outer groove walls, and on the other side of the brake disc the radially inner groove walls of the caliper are in abutment with the guiding pins. Between the opposite groove walls and the guiding pins, a clearance is provided such that contamination and corrosion cannot impair the slidability of the caliper. Although in a radial direction the caliper is supported at the brake support member by four surfaces only, four further surfaces are provided which ensure a sufficient connection between the caliper and the brake support member in the event of a broken spring. In order to obtain an even abutment of the caliper with the original four guiding surfaces, two adjacent guiding surfaces of the known sliding guide are arranged at a relative angle such that the caliper is urged into a central position between these two surfaces by the action of the clip spring. This known sliding guide has proven to be effective in practice, its manufacture, however, is still expensive.
Further, a sliding guide for the caliper of a floating caliper disc brake is known, as shown, for example, in German Patent DE-OS No. 2,124,030, wherein the one caliper end receiving the brake-actuating device has guide bores sliding on pins arranged parallel to the axis and formed fast with the brake support member, and the other end of the caliper is in positive engagement with a brake shoe guided axially slidably in the brake support member. Rubber bushings are inserted between the pins and the guide bores. However, the elasticity of the rubber bushings is not sufficient to prevent rattling of the brake shoe guiding the other caliper end. Therefore, additional springs are necessary between brake support member and caliper to clamp the two members relative to each other.